Not Applicable.
Not Applicable.
The present invention relates to data entry system, especially for cellular phones and personal digital assistants.
It has been desired to develop a data entry method applicable to portable electric devices like the cellular phones, palm top computers and so on. Such devices have narrow areas to implement the keys for data entry.
One of the proposed approaches for such a problem is to use small size keys, and special feature key tops are proposed (U.S. Pat. No. 4,310,753). Using this type of key tops, many keys can be implemented in a narrow area, but it is not easy to realize a comfortable data entry circumstance.
Another approach is to enter information like a character code or a function with a combination of the plural selected keys, so called chord method (U.S. Pat. Nos. 5,515,305, 5,552,782, 5,793,312, 5,993,089). But a log time practice is required to be skilled to use a chord type keyboard, because the user needs to remember the key combination for all characters. Furthermore a cellular phone is too small to implement a chord keyboard system with comfortable size keys.
With the present invention, character data are entered with two finger operations to a set of keys consists of three key groups. A key or none is selected from each key group by touching the keys, and the character to be entered is determined as the combination of the selected keys. The determined character is entered when one or two fingers release all the depressing keys.
There is a rule to select a key from the key group when plural keys are depressed in the key group. Therefor the keys can be arranged to a narrow area densely.
With the present invention, the status of the key operation, e.g. which keys are selected and/or which character is selected, is displayed. Therefor the operator can search right key operation looking at such display and, after that, the operator can enter the desiring character by releasing one of the fingers. So the keys can be arranged highly densely, and the operator needs not remember the key combination for all the characters to use.
By displaying a set of candidates of the characters to be determine, those are the set of the characters correspond to the set of the keys in a key group, the operator can search the desiring character rapidly.
With the reasons stated above, a comfortable data entry environment can be realized with a cellular phones utilizing the present invention.